Retractable spur knife device for veneer lathe

ABSTRACT

A retractable blade spur knife device for use with a veneer lathe which uses a fluid power cylinder to provide for the extension and retraction of the spur knife blade from the device. A toothed portion of the spur knife blade which is adapted to engage with teeth in a movable plunger member from the power cylinder provides adjustment means in the device to take care of wear resulting from repeated sharpenings of the cutting end of the knife blade.

United States Patent [56] References Cited UNITED STATES PATENTS 9/1899 Fenlason......................

[72] inventor RoyalC.Cady

Highbridge, Wis. 831,426

[21] Appl.No. [22] Filed 633,548 945,690 1/1910 Bush........... 2,720,898 10/1955 Bush et al.

June 9,1969 [45] Patented June29,l97l

[73] Assignee Universal Oil Products Company Des Plaines, lll.

FOREIGN PATENTS 6/1953 GreatBritain................

Primary ExaminerDonald R. Schran Attorneys-James R. Hoatson, Jr. and Philip T. Liggett ABSTRACT: A retractable blade with a veneer lathe which uses a fluid vide for the extension and retraction [54] RETRACTABLE SPUR KNIFE DEVICE FOR VENEER LATHE an m a lne lmm m m nke kwm mvfl pm S m a m v m P from the device. A toothed portion of the which is adapted to engage with teeth in a member from the power cylinder 4 Claims, 2 Drawing Figs.

in the device to take care 54 1mm 05 n lmM {51] Int.Cl............... [50] Field of Search.....

of wear resulting from repeated 209, 215 sharpenings of the cutting end of the knife blade PATENTEB JUN29 IHYI Figure 2 STROKE 0 "D II \RETRACTABLE MOVEMENT INVENTOR. ROYAL c. CADY a/c/fwzam,

414. L J d 0 ATTORNEYS RETRACTABLE SPUR KNIFE DEVICE FOR VENEER LATHE The present invention relates to an improved form of spur knife device for use with a veneer lathe and, more particularly, to an assembly which has adjustable coupling means between a power supplying fluid cylinder and an extensible-retractable form of knife blade for the unit.

In carrying out the peeling of veneer from logs in a veneer lathe, it is customary to have one or more spur knife blades or spur cutting means positioned along each side of the back portion of the lathe and generally on a movable carriage or pressure bar section which gradually moves the veneer cutting blade so as to maintain it in cutting contact with the side of the log. Each of the spur knives has a blade which projects outwardly, at a right angle with respect to a log held in a veneer lathe, and each will serve to cut, at each end of the log, a

straight side portion for the resulting strip of thin veneer being peeled from the log and transferred to a reel or to a conveyor. Where a single spur knife device is provided at each end of the lathe, then there is generally some lateral adjustability required in the holding of the spur device so that it may be positioned as close to the end of the log as possible. On the other hand, where a plurality of spur devices are used at each end of the lathe unit, then automatic operating means may be used to provide for the selective use of but one of the plurality of spur blades at each end of a log during the veneer cutting operation.

It may be noted that while various means may be utilized to bring a spur knife blade into cutting contact with the end of a log in the lathe, it is an improved construction and advantage, as provided by the present invention, to use a fluid power cylinder unit to effect the extension and retraction of the blade for the present assembly. The fluid power cylinder may be operated by a solenoid-type control valve which in turn, can readily be operated by electrical pushbutton means so that there is easy selectivity of a particular spur cutting blade from a plurality of side-by-side units that are mounted on, or in combination with a lathe unit for veneer production.

While various conventional means have been provided for removably mounting spur knife units in connection with veneer lathes such that they may be properly located and so that they can have their blades periodically sharpened, it is to be n noted that the present improved construction will permit adjustability as to blade extension to compensate for blade wear and repeated sharpenings, as well as blade removal from the device.

Broadly, the present invention provides a retractable form of a veneer lathe spur knife, which comprises in combination, an elongated base member having a longitudinal guide means to accommodate the movement of a knife member, an elongated knife member with at least a portion thereof adapted to engage with a move in said guide means of the base member, a movable plunger member having adjustable connection means providing engagement with said knife member, additional guide means from said base member'for said plunger member, and reciprocable power supply means connecting to said movable plunger member whereby there can be movement of the latter and said knife member.

Generally, the elongated knife member will have a cross section which is rectangular and sized to be a slide fit within a track or other suitable slotted type of guide means extending longitudinally through the base member of the unit. Thus, the knife blade can be readily extended or retracted from the forward end of the spur knife assembly by means of a reciprocable power unit such as an air cylinder or other fluid power cylinder means. Preferably, the fluid power cylinder will be mounted directly on the rear portion of the base member in order to easily connect with the reciprocable knife member.

A particular feature of the present improved design and construction, is the utilization of a special movable plunger as the connecting member between the piston rod of the fluid power cylinder and the movable knife member. Also, as indicated hereinbefore, a preferred unit has adjustability in the connecting means between the power supply unit and the knife member so that there may be compensation for wear in the end of the knife member as it is used and periodically sharpened. For example, in a preferred embodiment there is the use of opposing teeth in both the connection member and in the body of the knife membersuch that there may be varying engagements between the two so as to turn compensate for a gradual shortening of the cutting end of the knife member.

Reference to the accompanying drawing and the following description thereof will serve to illustrate one embodiment of the improved construction and arrangement for the spur knife assembly, as well as point out additional advantageous features in the method for effectingthe movement of an elongated knife member through an adjustable connection means from a power supply cylinder.

DESCRIPTION OF THE DRAWING FIG. I of the drawing is a diagrammatic isometric view indicating the general design and arrangement of the improved spur knife assembly.

FIG. 2 is a sectional elevational view through a portion of the unit, showing an adjustable connector for engaging the knife member with the power supply unit.

Referring now particularly to the drawing, there is indicated a lower base assembly 1 constructed to have a longitudinal rectangular form slot for an elongated knife member 2. A central slotted portion 3 in the base section 1 is, in this instance, provided by spaced rectangular form base members 4 and 4' which are tied together across their top portions by a forward plate member 5 and a rear plate member 6. As best shown in FIG. 2, the knife member 2 is formed from an elongated rectangular piece of bar stock sized to be a slide fit within the guide or slotted section 3 of base section 1. The forward end portion of the knife member 2 is indicated as being sharpened into a wedge shape and at the same time is slanted to have a lower sharp tip portion 2' which is capable of effecting the desired circumferential cutting of a log in the veneer lathe and, in turn, provide the straight edge portions to the veneer being peeled from the log.

As will be noted, the slot 3 in base member 1 is open at the bottom such that the veneer lathe carriage, or other supporting plate, will necessarily provide the lower slide surface for knife member 2. However, by this design and arrangement, when the base assembly 1 is demounted there is the easy dropping out and removal of knife member 2 from the device.

In order to provide the extensible and retractable operation for the knife member 2 in the present spur knife assembly, there is used a fluid power cylinder 7, such as an air cylinder, that is mounted longitudinally on the rear baseplate member 6 and within the center portion thereof so as to have its piston rod connect with a yoke or forked section 8 at the end of a movable plunger member 9. The latter is, in this embodiment, of a rectangular form and held within a guide means 10 extending upwardly from the forward plate portion 5 of the base section 1. As indicated diagrammatically in FIG. 1, the guide section 10 is formed of a top plate member 11 connecting to side sections 12 and 12 which, in turn, rest on plate member 5. Suitable capscrew or bolt members 13 may be used to pass through the guide members 11, 12 and 12' down into tapped holes provided in the base section 1. Thus, there may be removability of the entire guide section 10 where it may be desired to remove the plunger member 9.

As best shown in FIG. 2, the plunger member 9 is provided at its forward end portion with another yoke section 9 in turn adapted to hold, with bolt means 15, a vertically oriented toothed member 14. The lower portion of the toothed connector member 14 is cut or machined to have square teeth members 16 in turn sized and shaped to fit into a toothed rack section 17 extending along the upper edge portion of the rectangular form knife member 2. The toothed engagement provides adjustability for the location of the knife member 2 in the guide slot 3 of the base section I so as to, in turn, vary the amount of extension for the knife tip 2' from the forward end of the assembly. in other words, when the forward sharpened end of the knife member 2 is gradually worn and shortened by repeated sharpenings there can be a readjustment of the tooth members 16 for connecting member 14 into a more rearwardly portion of the teeth in rack section 17 of knife blade 2 so as to cause the forward extension of the latter from the spur knife assembly.

The amount of extendable movement, or retraction for the knife member 2 is primarily governed by the stroke for the fluid power cylinder 7 operating through the connecting plunger arm 9, with such movement or stroke being indicated by the letter D as shown at the top of FlG. 2. Also, the corresponding amount of movement is shown at the forward end of FIG. 2 for the knife tip 2 with respect to the base section 1. However, in order to insure a definite adjustment for the stroke and the corresponding knife member movement, there is provided an adjustment screw member 18 which is held within a threaded base or shoulder section 19 from the top and center of the forward plate member 5. The end of the adjustable screw member 18 is thus positioned to be in alignment with the forward end of the plunger member 9, or, more particularly, with the side of the connector member 14 which extends downwardly from the yoke section 9' whereby to limit stroke length D at this zone.

It should be observed that the present improved design is of particular advantage in having as assembly where the knife member 2 may be removed from the device for periodic sharpening operations while, at the same time, through the use of the toothed engagement between the upper edge portion of the knife member and connecting member 14, which in turn connects with plunger means 9, there is the provision for the desired longitudinal adjustability for the knife blade. This latter provision of course permits the use of a single knife member over a long period of time in the device. Still further, it will be observed that the use of a pneumatic cylinder or other fluid power cylinder provides a desirable automatic method of acquiring retractable movement for a knife member in a spur cutter such that the forward cutting edge of the spur knife blade will not be put into operation until such time as the veneer lathe operator desires its extension into a log that is positioned in the lathe.

More particularly, the retractable knife operation from the use of a fluid power cylinder means permits an improved overall design for the veneer lathe station in that a plurality of spur knife assemblies may be positioned on the rear carriage in a side by side manner, and at each end thereof, so as to provide selectively of a particular spur knife from one of the plurality at each end of the lathe carriage. In other words, the use of a plurality of spur knife devices at each end precludes the need of individual positioning for an individual spur knife device in order to accommodate a veneer peeling operation. Actually, with the plural use of cylinder-operated spur assemblies, the lathe operator, after having a log mounted within the chucks of the veneer lathe, can visually observe which of the plurality of spur knife assemblies should be placed into operation and by a suitable pushbutton arrangement of a solenoid valve for fluid control of a particular and properly positioned spur knife assembly and thus bring the spur cutter into operation at the end of a log.

It is not intended to limit the present improved design to any one method of forming the base section so as to provide a guide slot for the knife member. Also, it is not intended to provide any one type of guide means in combination with the base section for accommodating the reciprocating plunger member inasmuch as variations in shape and design may well be used for the connector members, as well as for the elongated knife blade members. Still further, it is not intended to limit the present improved design to any one type or shape of tooth, or toothed arrangement, in effecting the adjustable interconnection between the plunger member and the knife member; however, there shall be an extended length of teeth in at least one of the members so that there is the resulting longitudinal ad justability for the engagement of such members.

lclaim:

1. A retractable form of a veneer lathe spur knife device, which comprises in combination, an elongated base member having a longitudinal guide means to accommodate the movement of a knife member, an elongated knife member with at least a portion thereof adapted to engage with and move in said guide means of the base member, a movable plunger member having adjustable connection means providing engagement with said knife member, additional guide means from said base member for said plunger member, and reciprocable power supply means connecting to said movable plunger member whereby there can be movement of the latter and said knife member, said reciprocable power supply means comprising a fluid power cylinder mounted longitudinally on said elongated base member to provide a direct connection with said movable plunger member.

2. The spur knife device of claim 1 further characterized in that said elongated base member has a longitudinal slot along and through the lower portion thereof as said guide means and said knife member is of elongated bar stock sized to fit within such longitudinal slotted guide means in a manner whereby such knife member is removable from the lower face of the base member when the latter is removed from a support for the device.

3. The spur knife device of claim 1 further characterized in that an adjustment screw is provided on said elongated base member in alignment with said movable plunger member at a spaced distance from the end opposite said power supply means whereby to provide close adjustability for the reciprocating stroke of the latter.

4. A retractable form of a veneer lathe spur knife device, which comprises in combination, an elongated base member having a longitudinal guide means to accommodate the movement of a knife member, an elongated knife member with at least a portion thereof adapted to engage with and move in said guide means of the base member, a movable plunger member having adjustable connection means providing engagement with said knife member, additional guide means from said base member for said plunger member, the upper portion of said elongated knife member having a toothed rack section and a lower portion of said plunger member having a toothed section adapted to provide said adjustable connection means between said movable plunger and knife members, and reciprocable power supply means connecting to said movable plunger member whereby there can be movement of the latter and said knife member. 

1. A retractable form of a veneer lathe spur knife device, which comprises in combination, an elongated base member having a longitudinal guide means to accommodate the movement of a knife member, an elongated knife member with at least a portion thereof adapted to engage with and move in said guide means of the base member, a movable plunger member having adjustable connection means providing engagement with said knife member, additional guide means from said base member for said plunger member, and reciprocable power supply means connecting to said movable plunger member whereby there can be movement of the latter and said knife member, said reciprocable power supply means comprising a fluid power cylinder mounted longitudinally on said elongated base member to provide a direct connection with said movable plunger member.
 2. The spur knife device of claim 1 further characterized in that said elongated base member has a longitudinal slot along and through the lower portion thereof as said guide means and said knife member is of elongated bar stock sized to fit within such longitudinal slotted guide means in a manner whereby such knife member is removable from the lower face of the base member when the latter is removed from a support for the device.
 3. The spur knife device of claim 1 further characterized in that an adjustment screw is provided on said elongated base member in alignment with said movable plunger member at a spaced distance from the end opposite said power supply means whereby to provide close adjustability for the reciprocating stroke of the latter.
 4. A retractable form of a veneer lathe spur knife device, which comprises in combination, an elongated base member having a longitudinal guide means to accommodate the movement of a knife member, an elongated knife member with at least a portion thereof adapted to engage with and move in said guide means of the base member, a movable plunger member having adjustable connection means providing engagement with said knife member, additional guide means from said base member for said plunger member, the upper portion of said elongated knife member having a toothed rack section and a lower portion of said plunger member having a toothed section adapted to provide said adjustable connection means between said movable plunger and knife members, and reciprOcable power supply means connecting to said movable plunger member whereby there can be movement of the latter and said knife member. 